Conventionally, digitized radiation images have been obtained from an object by a radiation image conversion method using a radiation image conversion panel having a stimulable phosphor layer. The radiation image conversion method is referred to as a process in which a radiation having passed through an object is irradiated onto the stimulable phosphor layer to allow radiation energies corresponding to radiation transmission densities of various parts of the object to be accumulated in a stimulable phosphor and the radiation energies accumulated in the stimulable phosphor are emitted by stimulating light, then, the intensity of the thus stimulated emission is converted to electric signals, which are visualized as an image through image recording material such as photosensitive material or image displaying devices such as CRT (cathode ray tube) or LCD (liquid crystal display).
Recently, there has been developed a technique to obtain a radiation image conversion panel exhibiting extremely high sensitivity in which a stimulable phosphor layer is formed on a support through vapor deposition using a stimulable phosphor composed of CsBr as a crystalline parent component, for example, as described in JP-A No. 2001-249149 (hereinafter, the term, JP-A refers to a Japanese Patent Application Publication).
It is also known that formation of a stimulable phosphor layer composed of fine columnar crystals achieves enhanced sharpness. The fine columnar crystals accomplish a light guidance effect and cause stimulating light to reach the bottom of the columnar crystals with preventing scattering of the stimulating light, thereby achieving enhanced sharpness of the image of stimulated emission.
Accordingly, to obtain a radiation image conversion panel exhibiting enhanced sensitivity and sharpness, there has been desired enhancement of crystallinity of the stimulable phosphor layer and a stimulable phosphor layer exhibiting high transmittance for stimulating light and/or stimulated emission light.